I read where the specs from GM calls for 14.2 oz of lube in the box. I've got some NLGI #2 synthetic that I'll be using, and the amount seems excessive, especially given that the lube shouldn't liquify. Does the box really need to be slammed full?

Also, the gear teeth (worm & sector) have a some wear (manual steering). I've rebuilt the box with the basic $60 bearing/seal kit and wondering now if I should replace those high dollar parts... Can anyone give me a description on how much wear is ok?

 

You need to PM Jim Shea. He is the steering gear guru here on the boards.

BigBlockk

Later.....

 

The pitman arm bushing and pitman arm itself is a major wear problem. Stock clearance should be in the .001 range and you are probably in the .006 range. Stock replacement bushings will help but for a true good fit you need custom bushings.
If you can move the pitman arm at all with the box held tightly in the vise you have a problem.
End play in the pitman arm is also important. The little washer on the end of the pitman arm is our end play adjustment

 

To add:
If the sector shaft is not properly adjusted...it will seem like all parts and bushings are completely worn. You can add all the washers you want at the end of the pitman arm, but if you dont adjust the sector shaft...it wont make a difference...basicall all it will do is jamb the pitman arm gear to the gear housing (thats so extreme it would never happen anyway)

These steering gears are very very simplex.

The sector shaft adjustment works like this:
its actually a bolt (sorta) attatched to the top of the pitman arm in a slot...
Starting with steering wheel AT CENTER.
loosen the lock-down nut and back off several threads....tighten down the sector shaft adjustment "screw" ...this forces the pitman arm down into the gears (they are angled/beveled)...tighen until you feel tension...hold screw in place with screwdriver then tighten lock nut...then turn steering wheel side-to-side returning to CENTER....hold screw in place and loosen lock-nut again....tighten down scew again removing any left-over slack that turning the steering wheel has left as it "settled the gears".

DO NOT OVETIGHTEN...this will cause darting on the road...tighten until you feel tension...sometimes its helpful to tighten down alot and then back off a bunch (like cleaning the threads on a rusty bolt)...then slowely tighten to get to the "fresh-clean threads" so its easier to feel the actual tension of the gears touching.

Once you correctly adjust the sector shaft...you can then determine if you have an over abundance of tolerances anywhere...(I do nOT suggest, but) these things are so simple; I have seen king-pin bushings used as repair bushings for the pitman arm bushing, and lasted longer and was a better fit than the original GM bushing.



Jim

 

The only thing I have to add to Jim's great text is that it is impossible to accurately set the lash with the box in the car. It must be removed and done on a bench with an inch pound torque wrench. If not you will have the worst feeling steering you've ever experienced. Dave..

 

I blueprint/rebuild these, so I would to add the following.

As Norval said the biggest thing overlooked in rebuilding these boxes is the slop in the pitman shaft and bushings. I nver use the kit bushing unless someone wants a typical catalog job. Most used boxes are sloppy from day one,as are many of the production line units on these cars. I've seen guys sadi they rebuilt the boxes and they are no better, then dump $1,200 into an aftermarket rack system when in a lot of these cases a custom rebuild would have been all that was required and for under $300 in most cases.

The next thing to check is the lash screw shim under the lash screw in the pitman arm slot.This has to be under .002" I set them to .001. Again the kit parts are not going to get you there. I've had to grind a shim in every box I rebuilt to get there.

Next forget the fish scale, beam torque wrench approach to setting these up. If you want an ok job give it a shot with one of those, if you want the best setup use only a 0-30 in/lb dial torque wrench. I know there are plenty out there who will argue this point on several of the corvette forums on the web- all I can say is "it's your car,you get what you pay for" I sure as hell wouldn't drive it.

Grease, 11 oz is what I believe Jim listed years ago. When rebuilding them I add grease and work the worm back and forth to get it to settle , I do not top off as much grease as I can fill it with- it needs room to expand especially near headers.

Set the pre load to 3-5 in/lbs and set the lash to 11-12 in/lbs on center. There is no guessing or close with this- unless again you want an average job.

The gears will almost always have wear on them, even those on ebay with only 12k miles on them. I'd like to look over some of those boxes,I'd bet they are as sloppy as the high mileage boxes that come my way.

You can get a good idea on gear wear by looking at the box before rebuilding it. Look at the lash screw and see how many threads are showing above the jam nut. If there are a couple and the box is pretty tight then chances are very good the gears are fine. If the threads are just about gone the gears were adjusted in the past - either correctly or as in a lot of cases, incorrectly resulting in premature wear.

I've mentioned this before to help out guys doing this job,I hope it helps you. I've also had people send me boxes they bought and were in worse shape then the box they exchanged. One such box sticks in my mind because the guy was a local fellow who thought he scored a great deal at $150. When we went over the box, I found side play at .010", too much grease added, original bushing still in the box, lash shim at .007" and no preload or bearing lash- dialed in at 3 in/lbs. He got a used,worn box for $150- great score!

Ok I'll get off the soap box now.

Gary

 

How many threads left at the sector shaft adjuster (top of gear) is a useful tool to "eyeball" unseen inside wear or at least have a general idea...there is no guarantee with this method...but if you see green paint on the nut/threaded screw/top of gear housing...there is a good chance there is some lash adjustment to correct some of the tolerances.

I too have re-built many...in all honesty a person could get 10 complete used gear boxes and not have enough *good* parts to make one good one.
Kits to *rebuild* them??...over-rated...a person is better off machining his own parts to repair them correctly.

I did a 79 last summer where the owner (this was funny, but greasy):

1 removed the 4 bolts from the top...but couldnt remove the top..so..
2 unscrewed the lock-nut...but couldnt remove the top..so..
3 turner the sector shaft screw until the top came off.
4 added synth diff. lube (to make the gears have less friction...HAH!)
5 re-assembled the unit
6 asked me why it leaked and if I could re-seal it with a kit he had *in hand".
7 his sector shaft was adjusted so tight that you could turn in a parking lot and never make it to the steering stop...and, in the same turn, it would never move from that radius...it was stuck and had to be forced back to center.

And as gtr1999 stated...the sector shaft adjusting screw/lash screw...should never be flush with the lock-nut...and even worse if you have to find a narrow screwdriver to fit inside the nut to tighten.


Jim
(who has seen some really *intresting* things done to steering and suspension components)

 

i'm lurking this one

 

LOL...I just replied to your other lurk...lol

 

i wish i could write so well

 

Jim,
Interesting story. The top of thread look is good if a guy asks me at a show to look at his car. A quick look will sometimes tell a lot,like are the Ball joints riveted or bolted, are the upper control arm shaft round or square at the mounting bolts,does the rag joint have a "repair" kit in it, where the clutch rod adj nut nuts are set,etc.

One of the things that I find just bad advice is when I read about adding grease to the boix by removing the 2 cover screws or to adjust the lash screw and see how the car feels. You can very easily over adjust the box and it will feel better as it grinds the gears to useless junk in a short time.LOL!

Comp you can lurk,you're about the only one who admits to it anyway!

 

Thanks...it was an intresting repair...lol
I have used certain 18wheeler king-pin bearings to replace bushings on some very old manual steering gears...and I have to say that it worked very well, was a perfect fit that required no additional machining.
If I am not mistaken; I did this on an old International Scout with a 4cyl.
But I am kinda old and have been turning wrenches since I was in elementary school (back in the old days elementary school went to 8thgrade)

There really is some good repairs that can be done beside using "the rebuld kit".

I forgot to mention the deal about the green paint.
If its a drab geen (and I have even seen drab yellow)...its a paint that the factory put to know if the gear has been adjusted. I relly get a kick out of seeing the paint still there and perfectly in place.


Jim

ps.
Ever get the argument:
"I am telling you, nobody has ever worked on the front end!!"..and I look at the top ball joints and see where the rivets were cut (control arm scarred) and bolts and nuts holding the upper ball joint.

or

"I am telling you..nobody has ever added brake fluid!!"
but yet, I press the pistons in and brake fluid id pouring out of the MC practically blowing the lid off.....

I've heard them all....I was doing CSI on auto-repairs before CSI ws on TV...lol

 

i'd like to convert my box to the fast ratio 12:1 (i believe) from the stock ratio 18:1. Where to get the gears? I'm going to give it a go rebuilding it myself.

 

Flaming river make the fast ratio and Ecklers sells them.


When you get the chance could you PM me some info on the car you're using at Lime Rock? I'm not a racer but my friend is building his 78 to race there and wanted to know about suspension, tranny, and gears you're running there.

Thanks,
Gary

 

Thanks for the help, guys. My box wasn't too bad. The bushings are all good with no play at all in the shaft. The races were in good shape as well, but I replaced them anyway. There is still 3.5 threads showing on the adjuster screw, but had no shim. It measured .003 and I didn't have a .001 shim, so gonna live with the difference. Hard to tell if the ball bearings were worn any, so just cleaned everything up and dropped them back in.

Now for the grease deal... I ended up using maybe 10oz and it more than covered everything and still seemed excessive. I left the end plug out to see how much would be forced (pressure) on the inner bearing when the worm was worked. Sure enough, a good wad came out. Going on a buddie's experience, the extra pressure on the bearings caused some initial adjusting problems and soon afterwards developed scary loose steering. Given that the lube has changed over the years from gear oil to #2, has the inch-pound torque numbers changed with it? Seems that the thick grease would add extra resistance. Before installing the new kit and grease it was very smooth turning with a built-in resistance at the center point. Of course, the old stuff was more like gear oil. Now it's smooth as would be expected, but with at least two or three times the finger resistance. Uh, I'm using that "resistance" guesstimate since I haven't borrowed a torque wrench yet!

 

Nope torque specs are the same... I would have put all the bolts in though Chris... Dave..

 

Bolts?

 

The specs are the same. If 90 wt oil is used the best built box will leak. Grease is what should be used. The shim missing from under the lash screw isn't good but you have to decide on that. Like I said the kits get you close but to get the best you'll have to fit parts.
what sideplay did you end up with?

Good luck, let me know if you need any help in the future.

Gary

 

Yea the one you left out that let the grease squeeze out. Dave..

 

Ok, got a hold of a dial torque wrench (Mac). Here's how little I know... a total of 7 in.lb. (worm bearing preload and sector adjustment) was way more than I would have guessed if I just tried to 'wing it'. Guess there's a reason for the fancy tools!

Now for the prime/paint, 'cause lookin' good means workin' good. Correct?

Tnx for the help!